Should you eat when you have an infection? Separating Fact from Myth

October 13, 2025 •

4 min read

The old adage 'feed a cold, starve a fever' is largely a myth, and experts agree that maintaining nutrition is crucial when fighting any illness. So, should you eat when you have an infection? Yes, because your body requires more energy and specific nutrients to fuel a robust immune response and accelerate recovery.

Quick Summary

It is crucial to eat and stay hydrated when fighting an infection to provide the body with energy and nutrients for recovery. Despite reduced appetite, consuming nutrient-dense fluids and easily digestible foods supports the immune system and prevents malnutrition.

Key Points

Fuel Your Immune System: Eating provides the energy and nutrients your body needs to effectively fight off infection, as metabolism increases during illness.
Stay Hydrated: Fevers, vomiting, and diarrhea increase fluid loss, making proper hydration essential for all bodily functions and recovery. Opt for water, broth, or herbal tea.
Focus on Nutrient-Rich Foods: Prioritize proteins, vitamins (A, C, D, E), zinc, and omega-3s to support immune cell activity and reduce inflammation.
Avoid Inflammatory and Dehydrating Items: Limit sugar, processed foods, alcohol, and caffeine, which can hinder recovery and worsen inflammation.
Opt for Easily Digestible Options: Bland foods like bananas, rice, and toast are gentler on a sensitive stomach, especially with appetite loss or nausea.
Listen to Your Body: Don't force large meals if you lack appetite. Small, frequent portions are often more manageable and provide a steady stream of nutrients.
Fasting is Not Recommended: Despite some conflicting research, fasting is generally not advised during illness as it deprives the body of the energy required for recovery.

The Truth Behind the Myth: Why Eating Matters

When your body is fighting off a pathogen, it enters a hypermetabolic state, which means it burns more calories and energy than usual. Your immune system needs this fuel to produce new cells and antibodies necessary to defeat the infection. Forgoing nutrition when you are sick forces your body to break down its own tissues for energy, potentially delaying your recovery and weakening your overall immune function. Historically, the belief that you should 'starve a fever' was based on faulty premises that have since been disproven by modern medical understanding. A synergistic, downward spiral can occur when infection and malnutrition coexist, with each condition worsening the other. To break this cycle and give your body the best chance to heal, providing it with consistent, quality nourishment is essential.

What to Eat: A Nutritional Guide for Infection Recovery

Choosing the right foods and fluids can make a significant difference in how you feel and how quickly you recover. While a reduced appetite is common, focusing on small, frequent, nutrient-dense options can help.

Hydration is Non-Negotiable

Staying hydrated is perhaps the most important nutritional consideration when you're sick. Fevers, vomiting, and diarrhea can lead to fluid loss and dehydration. Proper hydration helps regulate body temperature, thins mucus to ease congestion, and helps flush waste products from your system.

Water: The best option for maintaining hydration.
Broth: Provides fluid, electrolytes, and some nutrients. The warmth is also soothing for a sore throat.
Herbal Tea: Hydrating and can help soothe a sore throat. Ginger and chamomile teas offer additional benefits.
Coconut Water: Replenishes fluids and electrolytes.

Prioritizing Key Macronutrients and Micronutrients

Different nutrients play specific roles in supporting your immune system's various functions.

Protein: The building blocks of your immune cells and antibodies. Lean meats, fish, eggs, beans, and yogurt are excellent sources.
Vitamins (A, C, D, E): Act as antioxidants, reducing oxidative stress on your cells and supporting immune cell activity. Key sources include citrus fruits, berries, carrots, and leafy greens.
Minerals (Zinc, Selenium, Iron): Play vital roles in immune function. Zinc, in particular, has strong evidence for supporting the immune system.
Healthy Fats (Omega-3s): Found in fatty fish, these fats are anti-inflammatory, which is beneficial when fighting an infection.
Probiotics and Prebiotics: Support gut health, a major component of your immune system. Yogurt with live cultures, kefir, and sauerkraut are good probiotic sources, while foods like garlic and bananas are prebiotic.

Easily Digestible Comfort Foods

When your stomach is upset, opting for bland, easily digestible foods can be the best approach. The BRAT diet (Bananas, Rice, Applesauce, Toast) is often recommended for soothing digestive issues.

What to Avoid During an Infection

Just as certain foods can aid recovery, others can hinder it by causing inflammation or dehydration. Limiting or avoiding these can help your body focus its energy on fighting the illness.

Sugary Foods and Drinks: Excess sugar can fuel inflammation, which can suppress the immune system and worsen symptoms.
Alcohol and Caffeine: These are diuretics, which means they increase fluid loss and lead to dehydration. Alcohol can also suppress the immune system.
Processed and High-Fat Foods: Greasy, fried foods can be difficult for your digestive system to process, diverting energy away from your immune response.
Hard or Crunchy Foods: If you have a sore throat, these foods can cause further irritation.

A Comparison of Foods for Infection Recovery


Best Foods for Recovery	Foods to Limit or Avoid	Reason
Broth-based soups	Cream-based soups	Provides hydration and electrolytes; cream is harder to digest.
Herbal teas	Caffeinated beverages	Hydrates and soothes; caffeine can cause dehydration.
Yogurt (with live cultures)	Sugary foods & desserts	Contains beneficial probiotics; sugar increases inflammation.
Lean protein (chicken, fish)	Processed meats (bacon, deli)	Provides amino acids for immune cells; processed fats can increase inflammation.
Berries, citrus fruits	Acidic juice (for sore throat)	High in vitamin C and antioxidants; can irritate an inflamed throat.
Ginger, turmeric	Excessively spicy foods	Anti-inflammatory properties; can cause stomach upset.
BRAT diet foods	Greasy, fried foods	Gentle on a sensitive stomach; hard to digest.

The Role of Fasting: A Complex and Evolving Picture

The concept of fasting during infection is complex and still under investigation. Some animal studies suggest that short-term fasting might alter the microbiome in a way that helps fight bacterial infections. However, other research indicates that skipping meals or fasting could compromise the immune system by impacting the number of circulating inflammatory monocytes, potentially leading to poorer outcomes. The effects also differ depending on the type of infection (viral versus bacterial) and the individual's overall health. Given the conflicting evidence and the increased energy demands of your immune system during illness, the general consensus for most people is to focus on a consistent, nourishing diet rather than attempting to fast. A healthy body is a well-fueled body.

Conclusion

When you are under the weather, focusing on nutrition and hydration is one of the most effective ways to support your body's recovery. The myth of starving a fever has been debunked; your immune system requires an abundance of energy and nutrients to fight off infection. Prioritizing fluid intake and consuming easily digestible, nutrient-dense foods is key. By making smart dietary choices and avoiding processed, sugary, or dehydrating items, you can provide your body with the best tools to heal. Always listen to your body and consult with a healthcare provider if your symptoms are severe, persistent, or if you have any concerns about your diet. A proactive approach to nutrition can make all the difference in getting you back on your feet. For more on how diet affects immunity, see this article from Harvard Health on strengthening your immune system.

Frequently Asked Questions

No, this saying is a myth. Your body needs fuel from food to fight both a cold and a fever. Restricting calories during any illness can weaken your immune system and slow down recovery.

The best drinks are hydrating fluids like water, broths, and herbal teas. If you have a fever or are experiencing vomiting or diarrhea, beverages with electrolytes like coconut water can be beneficial.

Loss of appetite is a common symptom of infection. While it's a natural response, it is important to try and consume small, frequent, nutrient-rich meals, as your body still needs energy to recover.

For most people, dairy products are fine. However, some believe it can thicken mucus, worsening congestion. This effect is not scientifically proven for everyone, but if it causes discomfort, you can opt for alternatives.

Soft foods and warm fluids are best for a sore throat. This includes broths, warm tea with honey (for adults), popsicles, and soft fruits like bananas and applesauce. Avoid hard or crunchy foods that can cause further irritation.

Yes, probiotics can be beneficial. Foods like yogurt and kefir contain live cultures that support a healthy gut microbiome, which is strongly linked to immune function. A healthy gut can aid in fighting off infections.

If you are struggling to keep food down due to nausea or vomiting, focus primarily on staying hydrated with small, frequent sips of fluid. Once your stomach settles, start with bland, easily digestible foods like the BRAT diet (bananas, rice, applesauce, toast).